SECTION 1: INTRODUCTION TO THE IAQ TOOL KIT... 1 SECTION 2: INTRODUCTION TO IAQ...

Transcription

1 August 2009

2 Table of Contents SECTION 1: INTRODUCTION TO THE IAQ TOOL KIT...1 SECTION 2: INTRODUCTION TO IAQ...2 IAQ Health Concerns... 2 IAQ Sensitivity... 3 What are the Common Causes of IAQ Problems?... 3 SECTION 3: IDENTIFYING AND ASSESSING IAQ ISSUES...5 Collecting Information on IAQ Problems... 5 Assessing IAQ Problems... 5 Assessment Steps... 6 Defining the Problem... 8 Resolving the Problem... 9 Sample Situations to Consider SECTION 4: STANDARDS AND GUIDELINES...13 SECTION 5: MANAGING AND CORRECTING IAQ PROBLEMS...18 Carbon Dioxide (CO 2 ) Carbon Monoxide (CO) Vehicle Exhaust Emissions Volatile Organic Compounds (VOCs) Formaldehyde Dust (Particulates) Thermal Comfort (Temperature and Humidity) Humidity/Moisture Lighting Noise Mould (fungi) Allergens and Microbes Odours Tobacco smoke Radon SECTION 6: HVAC PRIMER...38 APPENDIX A: EVALUATING IAQ CONSULTANTS...45 APPENDIX B: AIR TESTING & SAMPLING INSTRUMENTS...48 APPENDIX C: CHECKLISTS, FORMS, RESOURCES...53 Appendix C-1: Removing Visible Mould Appendix C-2: Sample Worker Complaint Form Appendix C-3: Sample Inspection Checklist for IAQ Appendix C-4: Sample Health Survey Appendix C-5: IAQ Problem Patterns and Causes Appendix C-6: Odours and Common Problems Appendix C-7: Health Complaints and Possible Causes Appendix C-8: General Lighting Checklist APPENDIX D: GLOSSARY...67 APPENDIX E: BIBLIOGRAPHY AND WEB RESOURCES...72

3 Section 1: Introduction to the IAQ Tool Kit The goal of this Tool Kit is to help you understand typical indoor air quality (IAQ) issues, and to suggest reasonable solutions to common problems. While many workplaces can use the Tool Kit, it is written with non-industrial settings in mind for those working in a building with offices, meeting rooms, some kitchen or lunch room facilities, with basic cleaning activities and a limited number or type of chemicals. The guidance may also apply to home businesses or very light industrial workplaces. Building owners, or those who lease office spaces, employers and workers will benefit from the information in this guide. This guide will help you identify the problem and provide advice about common approaches to recognizing and controlling IAQ problems. How the Tool Kit is Organized Section 1 Section 2 Section 3 Section 4 Section 5 Section 6 Appendix A Appendix B Appendix C Appendix D Appendix E Introduction to the Tool Kit Introduction to IAQ Why IAQ is important, as well as the typical health concerns of poor IAQ and common causes of IAQ problems. Identifying and Assessing IAQ Issues Guidance to help you recognize, identify and assess the extent and nature of IAQ issues. Sample forms and checklists are here too. Standards and Guidelines A concise list of IAQ-related regulations, standards and guidelines. Managing and Correcting IAQ Problems Common problems and ways to manage and resolve these. HVAC Primer Basics of how the HVAC system works, plus maintenance tips. Evaluating IAQ Consultants Guide to hiring an IAQ consultant to resolve workplace issues. Air Testing & Sampling Instruments If you have to test the air, this guide provides information on how it is done. Checklists, Forms, Resources Glossary of Terms Bibliography and Web Resources Indoor Air Quality Tool Kit 1

4 Section 2: Introduction to IAQ Good IAQ helps you provide a healthy and productive environment for all workers and others who occupy the area. There are many ways to help maintain and achieve good air quality, and to improve poor air quality. Most IAQ problems can be prevented with good maintenance, and resolved with simple and inexpensive measures. Why IAQ is Important In the past few decades, energy conservation measures have led to airtight building construction that can create problems with IAQ. Frequently the ventilation systems are set to minimize the amount of fresh air entering and circulating within the building. This restriction impacts indoor air by allowing a build-up of air contaminants within the building that are not properly removed. IAQ Health Concerns People spend a lot of time indoors for example, many office workers will spend their entire working day inside buildings. People who may have concerns about IAQ often mention the following symptoms as health concerns: dryness and irritation of the eyes, nose, throat, and skin, headache, fatigue, shortness of breath, hypersensitivity and allergies, sinus congestion, coughing and sneezing, dizziness, and/or nausea. You will notice that many of these symptoms may also be caused by other health conditions including common colds or the flu, and are not necessarily due to poor IAQ. This fact can make identifying and resolving IAQ problems more difficult. However, indoor air should be investigated as a cause, especially when people develop these symptoms within a few hours of being at work and they feel better after they have left the building or when they have been away from the building for a weekend or a vacation. Indoor Air Quality Tool Kit 2

5 IAQ Sensitivity Problems with IAQ do not affect all people in the same way. Some people may be more sensitive than others. Some people may be exposed to more contaminants in the building than others and they may experience symptoms earlier than other people. As air quality deteriorates and/or the length of exposure increases, more people tend to be affected and the symptoms tend to be more serious. It is also possible that some people can become sensitive to certain air contaminants as time passes. Some people may not be susceptible to IAQ problems in the early years of exposure but can become sensitized (react more severely or more often) as exposure continues over time. What are the Common Causes of IAQ Problems? IAQ problems can be the result of many factors. Building materials and furnishings, building equipment and activities, outdoor climate, and the building occupants themselves can play a role in IAQ problems. Common areas of concern include: Indoor air contaminants - chemicals, cleaners, dusts, moulds, fungi, odours, and vehicle exhaust emissions. Not enough outdoor air, poor air quality or poor air circulation. Is Air Contamination the Only Cause of these Symptoms? No. Feelings of discomfort and illness may be related to a number of issues in the total indoor environment. Other common causes may include: Noise Thermal Comfort (Temperature) Humidity / moisture Lighting It is important that these causes be investigated when assessing complaints. Section 5 on page 18 will help you identify and resolve these issues. Indoor Air Quality Tool Kit 3

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7 Section 3: Identifying and Assessing IAQ Issues When should I suspect an IAQ problem? When there is a problem with IAQ, people may experience the health symptoms that are listed in Section 2 on page 2. Since many of the symptoms are very similar to what we feel like when coming down with a cold or the flu (influenza), it is often difficult to say for sure if indoor air is the cause of the symptoms. However, it is prudent to investigate IAQ if people: develop these symptoms within a few hours of starting work and feel better after leaving the building, or after a weekend or vacation. In addition, if many people report similar symptoms, or if all of the people reporting symptoms work in the same area of a building, air quality issues should be suspected. Collecting Information on IAQ Problems There are several ways to collect information about IAQ. As a separate inspection, or as part of your routine workplace inspections: Incorporating IAQ aspects into the regular inspections by the work site health and safety committee (or representative) is one way to keep alert to potential problems. See Appendix C-3 on page 55 for a sample inspection checklist. Using worker complaint forms: Establish a reporting procedure that encourages people to report health concerns or unacceptable workplace conditions. A sample complaint form is provided in Appendix C-2 on page 54. Conduct a health survey: A health questionnaire that targets IAQ issues may be used to gather information about health conditions on a more formal basis. A sample health survey is provided in Appendix C-4 on page 56. Assessing IAQ Problems At this stage, you now suspect or think that you may have an IAQ problem, but are wondering how to: (a) make sure it is an IAQ issue, and (b) identify what is causing the problem. It is likely that people have reported symptoms that they believe are related to indoor air problems. Your job is to find out what might be the cause. Your initial investigation should focus on four main areas: Confirm that the ventilation system is operating properly (check the mix of fresh air, proper air distribution, clean filtration systems, humidification systems). Indoor Air Quality Tool Kit 5

8 Note: Temperature, humidity and the level of carbon dioxide (CO 2 ) are generally checked and used as a way to make sure that the HVAC system is in good working order. These factors are a starting point and you may need to assess air contaminants. Look for possible sources or causes such as a chemical, renovations, or mould. Rule out other possible causes such as noise, temperature, humidity, and/or lighting. Conduct a full health survey, if necessary, to help pinpoint sources and causes. Consider help and/or air testing by a qualified professional. There is no one single method that can be recommended that will cover all situations. Often, a common sense approach seems to work best. Who Should Investigate? Many people may play a role in helping to resolve an IAQ problem including the building owner, employer, property manager, and occupants. Who conducts your investigation will depend on your workplace, but in general, you should have one person who is the leader, and perhaps a small team, including a representative from the work site health and safety committee, or the union, if appropriate. The expertise of many other people such as health and safety or building maintenance personnel, and the experience of everyone in the workplace will all be important in finding the root cause of your IAQ problem. Assessment Steps The first step is to go on a fact finding mission. The steps taken may vary from one situation to another. The following 3 steps will help guide you towards a solution. 1. Gather background information and documentation, including: A map of the building layout or floor plans, marking areas with complaints. Complaint forms or other documentation such as records of recent renovations, or minutes from the work site health and safety committee meetings, if available. Complaints received by occupational health, managers or other staff. Maintenance records and design drawings for the HVAC system. Records of recent activities (routine and non-routine) such as cleaning, rug shampooing, painting, renovations, and/or equipment maintenance. 2. Take a walk through the building or area. Get a first hand look at the building design, floor plan, and ventilation system. Look for overall cleanliness and the operation of the HVAC system: Are there areas of concern such as improperly stored materials or chemicals? Indoor Air Quality Tool Kit 6

9 Do conditions in any area look like they may cause or promote mould growth including dampness, condensation, moisture or water damage? Is there any staining or discolouration of ceiling tiles, walls or carpets? Are any supply and exhaust air vents dirty? Can you feel the air moving around the supply and exhaust air vents? Are any vents blocked by papers, books or other items? Is the area dusty? Unsanitary? Do you smell any unusual odours? How does this area feel compared to other places you have visited? Is it warmer or colder? More or less humid? Are there drafts? Do you hear any unusual equipment noises? How many people are regularly in the area? 3. Talk to the people working in the area, and take the time to listen to their concerns. Who has IAQ concerns? Have they reported the symptoms already and to whom? Has someone modified a supply air vent because it was too noisy or drafty? Have there been changes to the ventilation system, renovations, the layout of the area, additional or new furnishing that may not be documented in the official logs and inventories? Using the Health Survey You can use the sample heath survey in Appendix C-4 on page 56 to gather more information about who is noticing symptoms and when. Remember to customize the survey, or add questions that are specific to your situation. You may choose to distribute the survey, or to conduct interviews in person. Interviews should be private, and specific health information about individuals is confidential. Using Worker Feedback Information gathered from workers will indicate potential problems as well as possibly highlighting an area where further investigation should be done. When you are trying to decide if an IAQ problem exists, it is important to remember the following: Not everyone will be equally sensitive. Even if only a few people are affected, do not ignore the possibility of a problem. Indoor Air Quality Tool Kit 7

10 Combined exposures may cause health problems even if the level of each of these exposures is below recommended limits. Health problems from exposure to a chemical may worsen in the presence of other chemicals. Defining the Problem When analyzing the results, compile the information you have gathered. What are: The type of complaints? The locations of the affected persons on the floor plan? The number of people affected? The timing of the complaints? The deficiencies noted to the HVAC system? The possible sources (such as improper storage, unclean areas, water damage)? When looking at your information, look for patterns in the locations and time of complaints. For example: Compare your findings from the background information and health questions to the floor plan. Are most of the people who have reported symptoms in one area? Compare your problem pattern information to Checklist C-5 on page 59. Does your IAQ problem fit into any IAQ problem pattern and to any of these causes? Odours can also be a good indicator of causes of IAQ problems. Review Checklist C-6 on page 61 to consider odours as possible connections to contaminants and health complaints. It is very likely that you will encounter a range of complaints during your assessment. Review Checklist C-7 on page 62 for common complaints and possible causes. Other Tips Renovations or additional building occupants will impact the ventilation system so compare the original HVAC design to the current use. Overcrowding may mean there isn t enough air exchanges for the increased number of people. Check the carbon dioxide (CO 2 ) level (or call an air quality professional to do this). CO 2 levels above 1000 ppm will indicate that there are issues with the ventilation system and it is possible that other contaminants are accumulating as well. Has a renovation blocked a vent or changed the airflow patterns? Is the air intake too close to the air exhaust? There may be a short circuit. Has new equipment been introduced (including photocopiers, printers, humidifiers, dehumidifiers)? Emissions from each piece of equipment can affect the air. Don t forget! Sometimes the answer can be simple! Always check the temperature and humidity levels to see if they are in the normal range. Make sure vents and ducts are not blocked. Indoor Air Quality Tool Kit 8

11 If you think your initial assessment has identified a cause or problem, work towards resolving the situation. Make the required changes, if you can, and see if the problem is resolved. Specific examples of how to manage and correct IAQ problems are presented in Section 5 on page 18. Resolving the Problem At the end of your assessment, you should be able to answer the following questions: What are the nature of the complaints? How many people are affected? Is there a connection to the building that can be related (such as time of day, location)? Are there obvious HVAC issues to be considered? Are there obvious internal or external sources of contaminants? If you have identified a potential source for your problems, try to identify a solution. Make the changes required. Evaluate if the change has resulted in better conditions. If not, are there other solutions that may help? If a solution cannot be found, or if other problems have been identified, you may need to hire the help of a professional. Monitor the Situation There are generally two ways to determine if your efforts to solve the IAQ issues have been successful. 1. Reduced complaints: If complaints are eliminated, or reduced, it may be a sign that the problems have been addressed. 2. Measurement of IAQ: If you are able to compare the properties of the air before and after, these measurements can show what actual changes have been made (includes temperature, humidity, air flow patterns, and air contaminant levels). Communication is Key It is a good idea to follow up or continue to monitor the situation, as often people will not make complaints once they realize that their issues are being addressed. On the other hand, people may continue to complain after a situation has been fixed but it may be that they are upset about how the situation was handled. As for any health and safety issue, you should always establish who will respond to the complaint, and how the complaint will be addressed. To help avoid these situations, it is a good idea to establish procedures for handling complaints and for communication before a situation develops. Be clear about how people can voice their concerns, and the steps that will be taken to investigate the issue. Let people know the purpose and scope of any investigation. If the investigation will take a period of time, post updates of any progress. Make the final results available, and encourage feedback. Encourage people to participate in the process. Indoor Air Quality Tool Kit 9

12 Refer to the following Assessment & Resolution flow chart as a guide. Indoor Air Quality Tool Kit 10

13 Sample Situations to Consider Renovation reality Business was booming and the marketing firm decided to create a new department. They retrofitted a manager s office into the existing building by adding new walls to one section of the existing cubicle (partition) layout. After construction was finished, staff in the area complained of headaches, fatigue and muscle aches. Investigation revealed that the new walls were not allowing air to circulate beyond the manager s office. A HVAC specialist was hired to make adjustments and add new vents. A complete rebalancing was required. Staff members were resurveyed, and they reported fewer headaches. However, muscle aches were still an issue. The HVAC was rechecked and confirmed to be in acceptable ranges. No other source was discovered. The manager next looked into the workload of individuals and found that many of those with muscle aches created graphical designs by working at their computers for over 6 hours a day. Job rotation was introduced as well as encouragement of micro-breaks where possible. Reports of fatigue and muscle aches are now far less frequent. Still searching Fantastic Fran s is a local customized t-shirt shop that does silk screening and embroidering. A few workers often complain about coughing, sneezing and generally not feeling well. A walk through assessment did not reveal any possible causes or sources. They decided to hire a consultant but while some problems were identified and addressed, some symptoms continued. While the HVAC system was operating normally, they decided to increase the number of air exchanges and increase the fresh air mixture. Some improvement was noted but still no exact cause was found. Kind neighbours Staff complained about an exhaust smell. It was particularly noticed by staff that started early in the morning. The HVAC system was checked to see if the air intake was close to the staff parking lot, but it was not. Next, they checked if the HVAC was switching to normal operations from its night reduction mode in time to accommodate staff that worked early hours. The HVAC was operating normally. A further investigation found that a nearby private school idled their buses in front of the office while waiting for the morning pick up time. The school was asked if the buses could wait elsewhere. The school was able to relocate the buses and was happy to help. Indoor Air Quality Tool Kit 11

14 Sometimes one solution can cause a different problem A new office building was receiving complaints that the office spaces were too bright. A lighting expert was hired, and the report indicated that there was too much natural light from the windows. As recommended, new mesh blinds were ordered and installed. Immediately after installation, many staff members complained of irritated and red eyes and a chemical smell. One staff member reported more serious health concerns, including shortness of breath, severe headaches, and other allergy-like symptoms. It doesn t add up A small accounting office was located in a strip mall complex. The office always had an odd odour they suspected that it might have something to do with either the bagel shop on one side, or the hair salon on the other. By late afternoon, the accounting office staff often found they were tired and had headaches. Several people reported watery eyes, and a burning in their throat. No causes were found in their office space, but they were located next to a hair salon that also employed an aesthetician (who mainly applied fingernail polish and decals). The accounting office requested that the mall owners hire an air quality consultant. The consultant found that there were several problems. The HVAC system was not calibrated to include an appropriate mix of fresh air, nor did it exchange the air adequately. In addition, the two offices shared ducting. The store owners negotiated with the mall operators to improve the air mixture and increase the number of air exchanges. This change did improve the air quality in both workspaces, but health complaints did not disappear entirely. They are further negotiating with the mall owners to make more substantial improvements to the HVAC system, including an exhaust fan for the aesthetician s work table that exhausts directly outdoors. The Health and Safety committee met, and since the blinds could not be removed, it was decided that the blinds should be fully extended when the staff left at the end of the day to allow for off-gassing. The HVAC system would run at its maximum air exchange rate and run at this full capacity for 24 hours a day. While more complaints were noticed immediately, after a few days the air quality was improving and no more general complaints where received. After about 2 weeks, the blinds were sufficiently off-gassed, and the HVAC system was returned to its normal settings. The one staff member who was more seriously affected still found it difficult to be in the building, and was allowed to work at home until her condition improved. To prevent future incidents, it was decided that all new fixtures or furniture would be allowed to off-gas in a separate building before being brought into the office space. Indoor Air Quality Tool Kit 12

15 Section 4: Standards and Guidelines This section summarizes the existing regulations, standards and guidelines that can help Alberta workplaces address IAQ issues. It is important to understand that most IAQ standards and guidelines are established to ensure the comfort of workers. So these values tend to be lower than regulatory values that are set to protect workers from possible health based hazards. Regulations cite values that must be complied with under the law. In Alberta, the regulatory limits are called occupational exposure limits (OELs). OELs are established for health-based reasons. Standards are set by special organizations with expertise but are not legally binding unless cited within a regulation. The IAQ values cited in standards are useful as a guide for workplaces where IAQ and comfort is a concern. Guidelines are recommended approaches or values that are useful but not mandatory. Various air quality resources are cited that relate to either indoor air quality, outdoor environmental standards, or workplace OELs for protecting the health of workers. Thermal Comfort (Temperature / Humidity) A common IAQ concern is the thermal comfort of workplace occupants. Thermal comfort means that when surveyed, a substantial majority (greater than 80%) of occupants report that they are comfortable. Changes in seasonal outdoor environments and occupant clothing have an impact on perceived comfort levels. ASHRAE recommends the following acceptable temperature values based on occupant clothing and relative humidity levels. Temperature / Humidity Ranges for Comfort Conditions Relative Humidity Acceptable Operating Temperatures C F Summer (light clothing) If 30%, then If 60%, then Winter If 30%, then (warm clothing) If 60%, then Source: Adapted from ASHRAE (reference 18) The Canadian Standards Association (CSA) also recommends similar temperature ranges Indoor Air Quality Tool Kit 13

16 for summer and winter. CSA Standard Z412 Guideline for Office Ergonomics [reference 36] recommends that for summer temperatures be from C, while in winter temperatures be from C. These temperature ranges are based on a relative humidity of 50%. Thermal comfort is also affected by drafts and temperature differences. Drafts that are caused by excessive air movement can be minimized by maintaining air velocity below 0.2 m/s (40 fpm) and by directing air supply away from occupants. Maintain workplace airflow so that temperature differences between the head and feet of occupants is not greater than 3 C. ASHRAE [reference 18] Humidity/Moisture Relative humidity levels below 20% are associated with increased discomfort and drying of the mucous membranes and skin, which can lead to chapping and irritation, and increases in static electricity. During very cold outdoor conditions, which are common in Alberta winters, humidity levels need to be reduced below 30% in order to avoid condensation on walls and windows. Condensation can lead to the development of moulds and fungi. The following table identifies the practical relative humidity level that can be achieved based on various low outdoor temperatures. Outdoor Temperature C Relative Humidity % >0 30 any 60% maximum In winter months, humidity may need to be reduced below 30% to avoid condensation. Other Parameters Adapted from Indoor Air Quality Guideline, Alberta Infrastructure (reference 16) Standards and Guidelines IAQ Issue Limits or Values Cited Carbon Less than 800 ppm (1) Dioxide * (CO 2 ) 1050 ppm (~300 ppm above outdoor levels) (4) 5000 ppm; 9000 mg/m 3 (8-hr) (3) Carbon Monoxide Vehicle Exhaust Less than 5 ppm (1) 25 ppm or 29 mg/m 3 (8-hr) (3) 5 ppm or 6 mg/m 3 (8-hr) (5) Refer to components such as Nitrogen dioxide, Sulfur dioxide, Carbon dioxide. Indoor Air Quality Tool Kit 14

17 Nitrogen Dioxide Sulfur Dioxide VOCs Formaldehyde Dust / particulates Lighting Noise (background) Mould Allergens/ Tobacco Smoke 0.3 ppm (1) ppm or 0.4 mg/m 3 (5) 3 ppm or 5.6 mg/m 3 (8-hr) (3) 0.3 ppm (1) ppm or 0.45 mg/m 3 (5) 2 ppm or 5.2 mg/m 3 (8-hr) (3) 5 mg/m 3 (CMHC) Keep specific contaminants below one-tenth of their OEL (1) 0.10 ppm (1) ppm (1-hr) (5) 0.75 ppm or 0.92 mg/m 3 (8-hr) (3) 0.04 ppm or 0.05 mg/m 3 (4) 0.1 mg/m 3 total dust (1) 0.1 mg/m 3 total suspended particulates (5) 10 mg/m 3 total particulate 3 mg/m 3 respirable particulate (3) mg/m 3 respirable fraction of dust (fine)** (7) Office: Lux (maintained) Computer: Lux (maintained) (1) Lux horizontal (computer use - intermittent to intensive) 500 Lux (filing or mail sorting rooms) (6) Adjust for aging workers, tasks, reduce glare 48 dba (general office area) dba (board rooms, private offices) (5) 50 dba (call centres) dba (open plan offices, private offices) (6) 35 dba (conference rooms, executive offices) Indoor air should reflect similar species but lower quantities than outdoor air 150 cfu/m 3 (3+ outdoor fungi species) >50 cfu/m 3 (only 1 species other than Cladosporium or Alternaria) (CMHC) up to 500 cfu/m 3 (summer if species primarily Cladosporium or other tree/leaf fungi) Limit or avoid exposures to fragrances, cigarette smoke, and exposures to dander-producing animals and insects. (1) Radon 200 Bq/m 3 (proposed) (8) Acceptable to > 80% occupants. Monitor CO Odours 2 concentrations* (alternative to monitoring odours) * CO 2 is often used to check the adequacy of the ventilation rate ** Respirable dust particles can be inhaled into the lungs (7) Indoor Air Quality Tool Kit 15

18 See Glossary definitions for: Bq/m 3 cfu/m 3 dba Lux mg/m 3 OEL ppm TWA Becquerel per cubic metre of air a measurement of radioactivity Colony forming unit of mould per cubic metre of air sampled Decibels measure sound levels, with a weighting to approximate human hearing A measurement of lighting level. The light of a candle at 1 foot is 10 Lux, while a sunny day outdoors is 32,000 Lux Milligrams per cubic metre of air Occupational exposure limit reflects a concentration of a chemical in air Parts per million reflecting a concentration of a chemical gas or vapour in air Time weighted average for an 8-hour workday Cited References of Air Quality Information 1. Alberta Infrastructure Indoor Air Quality Guideline An interdepartmental committee on IAQ chaired by Alberta Infrastructure prepared this guideline for the Government of Alberta facilities. [reference 16] 2. Alberta Occupational Exposure Limits The Alberta Occupational Exposure Limits (OEL) cited in the Occupational Health and Safety (OHS) Code (Schedule 1) reflect legal maximum allowable airborne limits for various workplace contaminants. The limits are based in part on the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLVs) which are modified from time to time. These limits are based on protecting workers. Especially sensitive individuals may be affected at lower exposure values. [reference 17] It should be noted that OELs are higher than actual airborne contaminant levels found in most office type workplaces. A common practice cited by the Alberta Indoor Air Quality Guideline is to use one-tenth of the OEL as an air quality guideline for office and related settings. Three types of limits are recommended: limits for 8-hour workdays, short-term exposure limits (15-minutes) or ceiling (not to be exceeded) limits. 3. ASHRAE Standard The American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE) publish IAQ standards. Thermal Environmental Conditions for Human Occupancy ASHRAE Standard recommends temperature, relative humidity, air speed and factors such as seasonal clothing. [reference 18] 4. Health Canada Residential Indoor Air Quality Guideline A recent guideline for formaldehyde is intended for residential exposures that are of a 24-hour nature. It is used for comparison to office workplaces. [reference 23] Indoor Air Quality Tool Kit 16

19 5. Alberta Ambient Air Quality Objectives These outdoor environmental air quality objectives (air concentration values) are established for specific chemicals for 1-hour, 24-hour or annual averaging periods. [reference 16] 6. Health Canada IAQ in Office Buildings: A Technical Guide This guide provides important guidance for IAQ and concentration of indoor contaminants. This technical guide was developed with a Federal-Provincial Working Group on IAQ in the Office Environment. [reference 8] 7. CSA Standard Z412 - Guideline for Office Ergonomics A Standard developed by the Canadian Standards Association to provide minimum requirements for office ergonomic issues such as lighting. [reference 34] 8. ASHRAE Standard The American Society of Heating Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE) publish IAQ standards. Ventilation for Acceptable Indoor Air Quality ASHRAE Standard recommends minimum ventilation rates and IAQ that will be acceptable to human occupants. ASHRAE 62.1 is intended to minimize the potential for adverse health effects. [reference 19] 9. Health Canada - Changes to Canada s Radon Guideline Health Canada s guideline on Radon is currently being considered for a potential change and this document provides information on the rationale for the new level. [reference 25] Indoor Air Quality Tool Kit 17

20 Section 5: Managing and Correcting IAQ Problems This section provides information on commonly reported indoor air contaminants as well as other IAQ issues. It will help you identify and eliminate IAQ problems. Other workplace factors affecting IAQ such as temperature, humidity and noise are also included. Outlined for each contaminant or issue are the source, potential health concerns and acceptable levels. Important tips on how to recognize and assess the issue will help pinpoint the root cause(s). Best practices in managing and correcting problems are also covered. Common Issues Carbon dioxide Carbon monoxide Vehicle exhaust emissions Volatile Organic Compounds (VOCs) Formaldehyde Dust (particulates) Temperature Humidity/Moisture Lighting Noise Mould Allergens and Microbes Odours Tobacco smoke Radon Carbon Dioxide (CO 2 ) Source Carbon dioxide is found naturally in the air. People are also a source of CO 2. When people breathe, oxygen is inhaled and carbon dioxide is exhaled. The carbon dioxide level builds up throughout the day where there are too many people in a poorly ventilated area. Health Concern CO 2 is not a toxic gas. It is primarily an indicator of how well the ventilation system is working. Some people may experience headaches at concentrations above 1000 ppm because of poor air circulation. The headache normally goes away when the person leaves the building. Indoor Air Quality Tool Kit 18

21 Levels The recommended guideline CO 2 level is about 1050 ppm or about 700 ppm higher indoors than outdoors (ASHRAE ). To achieve this level in offices, the recommended outdoor air intake is 5 cubic feet per minute (cfm) per person, plus 0.06 cfm per ft 2. Recognizing and Assessing the Problem The normal outdoor concentration of carbon dioxide is around 350 ppm. Generally people exhale carbon dioxide at a rate of 0.3 litres per minute (L/min) while doing light work, which means indoor CO 2 levels will rise above outdoor levels. The carbon dioxide level indoors builds up throughout the workday and peaks in the late afternoon especially in areas with too many people. Complaints about stale air or stuffiness are more frequent when CO 2 concentrations reach above about 1050 ppm. Managing and Correcting the Problem The CO 2 level is a common marker of how well the ventilation system is working. The rate of CO 2 removal from an area is related to the rate of air being removed from the space as well as the rate of fresh air entering the ventilation system from outside. The amount of outdoor air needed is based on the occupancy and the size (area) of the room or space. Keep in mind that the ideal airflow rate varies for different types of facilities based upon the level of activity, since greater activity generates higher levels of CO 2. Make sure the HVAC system is properly designed for the size of the space, number of occupants, heat sources and amount and location of contaminant releases Increase outdoor air intake to offset higher numbers of people and contaminants produced from other sources Make sure air supply and intake openings are not blocked Ensure fresh air intakes pull in uncontaminated air Carbon Monoxide (CO) Source Carbon monoxide is a colourless, odourless, toxic gas. It is generated from incomplete combustion of fuel-fired equipment, heating or cooking appliances. It may leak from the flue of gas vents of furnaces, hot water heaters or boilers. It can also be found in tobacco smoke and motor vehicle exhaust. Health Concern Carbon monoxide interferes with the blood s ability to carry oxygen, and thus can limit a person s oxygen intake. Short-term exposures below 50 ppm normally do not Indoor Air Quality Tool Kit 19

22 cause adverse effects in healthy people. Carbon monoxide causes increasingly severe toxic effects as the concentration and duration of exposure increase. The effects include mild headache (50 ppm and above) to severe headache (above 200 ppm); weakness, dizziness, nausea, fainting (above 400 ppm); increased heartbeat, irregular heartbeat (above 1200 ppm); loss of consciousness and finally death (above 2000 ppm). These symptoms are usually seen sooner or at lower concentrations if there is a heavy workload or if the exposed person has heart disease. Some people may be more sensitive than others to CO in the air, for example, if they are pregnant, have cardiovascular problems, or smoke. Levels Levels of CO should be 5 ppm or less - well below the levels that cause health effects. Recognizing and Assessing the Problem Install and maintain monitors in areas where CO can be generated: furnaces, gas stoves, gas water heaters Identify CO sources outside the building such as vehicles left running at loading docks, parking garages and industrial activity. Check to see how closely located these potential sources are to air intake and building entry points. Managing and Correcting the Problem Check CO detectors or monitors to ensure that CO is not present. Ensure ventilation systems are well maintained in areas with a potential for generating CO. Make sure all fuel-burning devices are properly installed, used and maintained. Never use portable equipment within a building since these are not properly ventilated. Make sure that potential pathways of CO to building areas from adjacent parking garages and loading docks are well sealed, and parking garages are well ventilated to control CO concentration. Maintain positive air pressure (if possible) in occupied areas. Keep areas around fuel burning devices clear of any items that could restrict air circulation. Vehicle Exhaust Emissions Source Cars, diesel-powered vehicles and diesel generators can generate exhaust emissions. These emissions contain a variety of air contaminants, including carbon monoxide, nitrogen oxides such as nitrogen dioxide, sulfur dioxide, coal tar pitch volatiles, polyaromatic hydrocarbons, and more. These exhaust emissions can be generated inside building parking garages or may enter buildings through outdoor intakes that Indoor Air Quality Tool Kit 20

23 are close to these sources. They may also be generated by improperly vented sources inside buildings. Health Concern Exposure to vehicle exhaust emissions may cause shortness of breath and irritate eyes, nose, throat and respiratory tract. Levels Vehicle exhaust emissions contain a wide range of contaminants that should be avoided. Beside carbon monoxide, the two predominant chemicals in these emissions - nitrogen dioxide and sulfur dioxide - should both be kept below 0.3 ppm, carbon monoxide should be kept below 5 ppm. Recognizing and Assessing the Problem The smell of diesel exhaust is very distinctive. Check the possibility that emissions from vehicles and combustion sources may be contaminating indoor air. Investigate the path a source may be taking to get into the building. Managing and Correcting the Problem Ensure ventilation systems are operating properly and are well maintained Ensure that pathways of vehicle exhaust to building areas are well sealed and building parking garages are well ventilated. Reduce vehicle emissions by turning off engines near buildings. Make sure all fuel-burning devices are properly installed, used and maintained. Keep areas around fuel-burning devices clear of any items that could restrict air circulation. Have combustion appliances routinely inspected and serviced by a qualified person. Volatile Organic Compounds (VOCs) Source VOCs are organic chemicals such as alcohols, esters and petroleum distillates. There are many, many different sources of VOCs including cleaning products, paints, coatings, paint removers, paint thinners, glues, caulking, carpets, photocopiers, air fresheners, perfumes, disinfectants, pesticides, and tobacco smoke. Health Concern VOCs are consistently present in higher concentrations indoors (up to ten times higher) than outdoors. At low exposure levels, symptoms include fatigue, headache, drowsiness, dizziness, weakness, blurred vision, skin and eye irritation and general Indoor Air Quality Tool Kit 21

24 discomfort. As the exposure level increases, people may experience unpleasant odours, respiratory irritation, tightness in the chest, nausea and confusion. Some highly sensitive individuals may be affected at very low concentrations. Levels Keep specific chemical contaminants to one-tenth of their occupational exposure level. Recognizing and Assessing the Problem Check the following to assess the potential for VOC release: Presence of new building materials, furniture or carpets. Recent renovations involving paints, glues, and other products. Review MSDS of cleaning or other commonly used products. Inadequate local exhaust in chemical storage area. Possibility of contamination from other areas in the building or outside air through the ventilation system. Manufacturer information on emissions from carpets, office furniture and building materials. Managing and Correcting the Problem Select low-voc materials. When purchasing new products, ask for information from the product suppliers about VOC content and emission rates. Allow new building materials and office furniture to air out (off-gas) in a well-ventilated storage area before installing them. When installing new materials, such as carpets, try to install immediately before an unoccupied period such as a weekend. Maintain a maximum ventilation rate for at least two weeks (24/7) to help flush out emissions and odours. Store chemicals such as solvents, paints, cleaning liquids, and paint thinners in a separate storage room with a separate exhaust fan. Make sure there is a separate exhaust fan in photographic and printing rooms. Keep containers closed when they're not in use. Formaldehyde Source Many building materials, especially new materials and furnishings, are potential sources of formaldehyde. These items include carpets, particleboard furniture, glues and adhesives as well as burning cigarettes and other tobacco products. Slow offgassing from these materials can cause a build-up of formaldehyde in indoor air. The Indoor Air Quality Tool Kit 22

25 rate of build-up depends on the emission source, the rate of outdoor air intake by the ventilation system, the humidity and the temperature. Health Concern Formaldehyde gas is an irritant and respiratory sensitizer. Symptoms of exposure include burning eyes, sore nose and throat, nosebleeds, coughing, headaches, nausea, dizziness, and breathlessness. Some sensitive individuals may notice symptoms at concentrations as low as 0.01 ppm. Formaldehyde is considered to be a known or suspected human carcinogen. Levels Levels of formaldehyde should be 0.1 ppm or lower as a guideline. Levels of carcinogens should be kept as low as reasonably possible. Recognizing and Assessing the Problem Although formaldehyde has a pungent odour, people may not realize they re being exposed to it because they can become accustomed to the smell. The odour of formaldehyde is not a reliable warning signal for exposure as the odour threshold level for many people is higher than the exposure limit. Have adequate ventilation where potential sources of formaldehyde are present to keep the concentration low. Managing and Correcting the Problem Select products with low formaldehyde emission levels if possible. Off-gas new building materials in a storage area before installing. Increase the amount of fresh air and airflow in areas of new furniture and carpets. Seal potential emission sources with a barrier such as polyurethane varnish. Do not recirculate formaldehyde-contaminated air. Dust (Particulates) Source Common indoor sources of dust include humidifier additives, poor housekeeping, inefficient vacuum cleaners, scale, rust, building materials, fungal spores, smoke, duct pipe insulation, carpet fibres, and paper fibres. Outdoor sources include airborne pollutants, construction activity, traffic activity, industrial emissions, and releases from fires and accidents. Indoor Air Quality Tool Kit 23

26 Health Concern The health hazard potential of specific dusts depends on their toxicity and on their particle size. Excessive levels of dust particles can affect the skin, eyes and respiratory system. Symptoms include irritation of the eyes, nose, throat and skin as well as coughing, sneezing, and respiratory problems. Levels Alberta IAQ guidelines recommend keeping total dust levels below 0.1 mg per cubic metre of air (mg/m 3 ). There are also specific OELs for a variety of dusts. IAQ levels should be kept below 10% of the OEL. Recognizing and Assessing the Problem There is the potential for dust in indoor air where there is: exposed building material (e.g. concrete, insulating material) renovation and retrofit activity dust in the air intake dust and debris in the air delivery and return dampers dusty filters dust deposits and/or odours around humidifiers dust and dirt build-up around diffusers use of personal ultrasonic humidifiers cigarette smoke handling of dusty materials paper shredding machines Managing and Correcting the Problem Use appropriate filters for the air handling system. Establish a schedule and routine to: o Inspect and change air filters o Clean air circulation system o Clean areas where dust settles o Dust surfaces with a damp cloth or cloth-covered duster. Change cloths often. Use local exhaust in areas where there is excessive dust from renovations or movement of materials. Provide negative air pressure and local exhaust in smoking rooms. Do not recirculate air that contains excessive levels of dust. Indoor Air Quality Tool Kit 24

27 Use a vacuum cleaner designed for use with and equipped with a high-efficiency particulate air (HEPA) filter. Change bags before they become full. Use entryway mats at all building entrances. A lot of dirt comes in through doorways and a mat to wipe your shoes will help. Thermal Comfort (Temperature and Humidity) Source Thermal comfort means that a person feels comfortable - they are neither too cold nor too warm. It can be achieved when the air temperature, humidity and air movement are within the specified range often referred to as the comfort zone. Even with ideal conditions cold or warm walls, ceilings or floors can cause local air temperature differences that may cause discomfort. Drafts caused by excessive air movement may also be a factor. Temporary or permanent changes to the original floor plan can affect the performance of the HVAC system. Factors contributing to poor thermal comfort include thermostats that are poorly situated, set too high or too low, and too few for the space. Sources of radiant heat (very warm or very cold surfaces) such as poorly insulated windows, walls and floors can also cause people to feel uncomfortable as they can create air drafts. Health Concern In an office that s too warm, occupants may feel lethargic or tire quickly. An office that is too cold causes occupants to feel restless and easily distracted. Even minor deviation from comfort may be stressful and affect performance. Workers already under stress are less tolerant of uncomfortable conditions, and are less productive. People s age, activity level, health conditions and clothing vary widely and so do personal temperature preferences. Levels Ideally, air temperature in an office should be kept at a range that most people find comfortable. The goal should be to maintain an office temperature that will satisfy at least 80% of the occupants. The season, relative humidity, clothing and activity level of building occupants may factor into the comfort zone. In summer, temperatures of C are recommended for comfort, while in the winter when relative humidity is closer to 30%, recommended temperatures are from C. Indoor Air Quality Tool Kit 25

28 Temperature / Humidity Ranges for Comfort Conditions Relative Humidity Acceptable Operating Temperatures C F Summer (light clothing) If 30%, then If 60%, then Winter If 30%, then (warm clothing) If 60%, then Adapted from ASHRAE (reference 18) Drafts that are caused by excessive air movement can be minimized by maintaining air velocity below 0.2 m/s (40 fpm) and by directing air supply away from occupants (ASHRAE see reference 18). Maintain workplace airflow so that temperature differences between head and feet of occupants is not greater than 3 C. Recognizing and Assessing the Problem You have a possible problem with thermal comfort if: occupants complain about feeling drafts or being too hot or too cold. portable fans or space heaters are being used. Note their location with respect to diffusers and perimeter heaters. there is condensation, frosting or other moisture on windows. Managing and Correcting the Problem Try to maintain the workplace environment so that at least 80% of the occupants are satisfied. Consider these other factors: Check that thermostats and temperature sensors in HVAC system are working properly. Check that setback and setup temperatures are correct. Allow sufficient time before workers start work to have warmed/cooled the workspace. Use blinds, perimeter heating and well-insulated windows to reduce warm or cool radiant temperature fluctuations. Before reconfiguring an office space, consider the impact on diffuser location and airflow volume. Before changing the number of occupants in an office, consider the impact on HVAC performance. Indoor Air Quality Tool Kit 26